Optical disc apparatus

ABSTRACT

In an optical disc apparatus, a harsh blow sound due to collision of first stoppers of a tray and third stoppers of a main chassis when the tray reaches to a terminal position of drawing thereof is reduced. When a second stopper of the tray contacts with the front end portion of a cam slider, the front end portion of the cam slider is elastically deformed so that moving speed of the tray is largely decelerated. Consequently, the blow sound due to contact of the first stoppers of the tray and the third stoppers of the main chassis is radically reduced.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an optical disc apparatus used forreading and writing data with respect to an optical disc such as a DVD(Digital Versatile Disc), and so on, and especially relates to anoptical disc apparatus having drawer mechanism of a tray on which anoptical disc is disposed.

2. Description of the Related Art

In a conventional optical disc apparatus, for example, shown inlaid-open bulletin of unexamined Japanese Patent Application No.2002-334502, stoppers are formed on both of a tray and a chassis of theoptical disc apparatus so as to stop the tray at a terminal position ofthe drawing of the tray. However, in such an optical disc apparatus, thestopper formed on the tray contacts to the stopper formed on the chassisat the terminal position of the drawing of the tray, and a harsh blowsound occurs. For preventing the occurrence of the harsh blow sound, aninclined plane, which is to be contacted with the stopper of thechassis, is formed in the vicinity of the stopper of the tray, so as toapply a load to the tray just before the end of the motion for drawingthe tray. Thus, the moving speed of the tray is rapidly decelerated, andthe intensity of the blow sound can be reduced. However, there is fear aparticle ingredient of the lubricant, which is applied to preventabrasion such as the inclined plane, is scattered in the apparatusinside, and to give bad influence to movement of the apparatus, when thetray is moved frequently. In addition, retreat movement of the traycannot be performed smoothly, when the fine particle lubricant comes offfrom contact portions of the tray and the chassis.

In another conventional optical disc apparatus, for example, shown inbulletin of Registered Japanese Utility Model No. 3094496, anelastically deformable portion of resin is formed on a tray so as to bedeformed when it contacts on an inner face of a chassis of theapparatus. In addition, a laid-open bulletin of unexamined JapaneseUtility Model Application No. 2-72457 shows a mechanism for moving arevolving table for revolving an optical disc up and down with drivingforce to draw a tray.

SUMMARY OF THE INVENTION

A purpose of the present invention is to provide an optical discapparatus, in which a blow sound due to collision of the stoppers of thetray and the chassis at the terminal position of drawing of the tray canbe reduced with using no fine particle lubricant.

An optical disc apparatus in accordance with an aspect of the presentinvention comprises: a main chassis; a tray, to which an optical disc isdisposed, movably held on the main chassis and drawn from the mainchassis in a predetermined direction; a driving mechanism provided onthe main chassis for reciprocally moving the tray in the predetermineddirection; and an elastically deformable member which contacts the trayjust before a terminal position of drawing of the tray from the mainchassis where the drawing motion of the tray is stopped in a manner sothat moving speed of the tray is decelerated due to elastic deformationof the elastically deformable member.

By such a configuration, kinetic energy of the tray is consumed toelastically deform the elastically deformable member when theelastically deformable member contacts the tray just before the terminalposition of drawing of the tray, so that moving speed of the tray islargely decelerated. When the tray reaches to the terminal position ofdrawing the tray, the moving speed of the tray has become very slow.Consequently, blow sound due to collision of the tray and the mainchassis is radically reduced, so that a quiet optical disc apparatus canbe provided.

When the elastically deformable member is made of a material superior towear resistance and having a coefficient of elasticity smaller than thatof a material of the tray, it is no need to spread a fine particlelubricant to contacting portions of the tray and the elasticallydeformable member. Consequently, there is no fear to give bad influenceto movement of the optical disc apparatus due to scattering of thepowder ingredient of the lubricant in the inside of the apparatus.Smoothness of the drawing motion of the tray can be maintained inlong-term use.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross sectional side view showing a constitution of anoptical disc apparatus in accordance with an embodiment of the presentinvention;

FIG. 2 is a plan view showing an essential part of the above-mentionedapparatus;

FIG. 3 is a perspective view showing a rear side shape of a tray of theabove-mentioned apparatus;

FIG. 4 is a side view showing a cam slider and a drive machine chassisof the above-mentioned apparatus; and

FIGS. 5A, 5B and 5C are plan views showing motion of drawing of the trayof the above-mentioned apparatus in chronological order.

DETAILED DESCRIPTION OF THE EMBODIMENT

An optical apparatus in accordance with an embodiment of the presentinvention is described with reference to figures. FIG. 1 shows aconstitution of an optical disc apparatus in accordance with theembodiment.

The optical disc apparatus 1 comprises a tray 2 which is used forloading an optical disc into an inside of the apparatus, a drive gear 3(see FIG. 2) for moving the tray 2, an optical pick-up 4 which is usedfor writing and reading data on and from the optical disc, a revolvingtable 5 for supporting and rotating the optical disc, a movable chassis6 on which the optical pickup 4 and the revolving table 5 are mounted, acam slider 7 for rotationally swinging the movable chassis 6 around apivot 61, a main chassis 8 on which the movable chassis 6, the camslider 7, and so on are mounted, and a cover 9 for covering theabove-mentioned elements.

FIG. 2 shows a visualized constitution of an essential part of theoptical disc apparatus 1, and FIG. 3 shows a structure of the tray 2.The tray 2 has a concave portion 21 on which an optical disc isdisposed, a first rack 22 which is engaged with a lower stage gear 31 ofthe drive gear 3, and a guide groove 23 which is engaged with a boss 71of the cam slider and serves as a guide when the tray 2 is drawn. Theconcave portion 21 is formed on a front face of the tray 2, and thefirst rack 22 and the guide groove 23 are formed on a rear face of thetray 2. The tray 2 is reciprocally movable in a direction shown by arrowA by the drive gear 3 and the can slider 7

The tray 2 further has a pair of first stoppers 24 which contacts a pairof stoppers 83 formed for protruding on the main chassis 8 at a terminalposition of motion of drawing of the tray 2 so as to stop the motion ofthe tray 2, and a second stopper 25 which contacts a front end portion73 of the cam slider 7 at a position just before the terminal positionof drawing of the tray 2. The first stoppers 24 are provided in bothside faces of the tray 2 in the vicinity of the rear end thereof. Thesecond stopper 25 is provided at a position on the rear face of the tray2 where the second stopper 25 can be contacted with the front endportion 73 of the cam slider 7 when the tray 2 is positioned just beforethe terminal position of drawing thereof. In addition, the tray 2 andthe main chassis 8 are molded of relatively hard synthetic resin such aspolystyrene to secure necessary strength.

The drive gear 3 is a two stage gear having the lower stage gear 31engaging with the rack 22 of the tray 2 and an upper stage gear 32engaging with a rack 74 of the cam slider 7. The drive gear 3 is rotatedfor moving the tray 2 in the direction shown by arrow A and for movingthe cam slider 7 in a direction shown by arrow C, when it receives adriving force transmitted through a plurality of gears (not shown) froma driving source such as a motor (not shown).

The optical pick-up 4 (see FIG. 1) is arranged to face a recordingsurface of an optical disc loaded on the revolving table 5. When data iswritten on the optical disc, the optical pickup 4 irradiates laser beamof higher power to the recording surface of the optical disc while theoptical disc is revolved. Alternatively, when data is read out from theoptical disc, the optical pickup 4 irradiates laser beam of lower powerthan that used for writing the data and receives reflection beam fromthe recording face of the optical disc.

The revolving table 5 is coupled with an output shaft of a spindle motor51 so as to be rotated with holding the optical disc owing to a drivingforce of the spindle motor 51. The optical pickup 4 and the spindlemotor 51 are put on the movable chassis 6.

The movable chassis 6 has the above-mentioned pivot 61 at an end whereoptical pick-up 4 is put on, and a boss 62 at the other end. The pivot61 is rotatably borne on fulcrums 81 in a manner so that the movablechassis 6 can be turned in a direction shown by arrow E. The boss 62 isengaged with a cam groove 72 formed on the cam slider 7.

FIG. 4 shows side views of the movable chassis 6 and the cam slider 7which are watched from a direction shown by arrow X in FIG. 1. The camslider 7 is made of a synthetic resin such as polyacetal which issuperior to wear resistance and have a coefficient of elasticity smallerthan polystyrene which is used for forming the tray 2, the main chassis8, and so on. The cam slider 7 is molded to have an L-shaped section(see FIG. 1). The cam slider 7 has a boss 71, which is to be engagedwith the guide groove 23 of the tray, on an upper face 76 facing thetray 2 (see FIG. 1). The above-mentioned cam groove 72 is formed on aside face 77 of the cam slider 7 facing the movable chassis 6. The camslider 7 is slidably held on a slider support 82 of the main chassis 8like a cantilever. A second rack 74, which is to be engaged with theupper stage gear 32 of the drive gear 3, is formed at a front endportion 73 of the cam slider 7.

The main chassis 8 has the above-mentioned fulcrums 81 for rotatablybearing the movable chassis 6, the slider support 82 for slidablysupporting the cam slider 7 and a pair of the stoppers 83 to becontacted with the first stoppers 24 at the terminal position of drawingof the tray 2 (see FIGS. 1 and 2).

During initial phase of drawing of the tray 2, the cam slider 7 isdriven by the drive gear 3 so as to slide in a direction shown by arrowC1 in FIG. 4. Following to the movement of the cam slider 7, the boss 62of the movable chassis 6 moves along an inclined portion 72 a of the camgroove 72. Consequently, a free end of the movable chassis 6 comes downin a direction shown by arrow E1 with the revolving table 5, so that anoptical disc can be unclamped from the revolving table 5.

Subsequently, the drawing motion of the tray 2 is described withreference to FIGS. 5A to 5C. As can be seen from FIG. 5A, when the tray2 is pulled in the inside of the main chassis 8, the drive gear 3 isdisengaged with the first rack 22 of the tray 2. When the drive gear 3is rotated in a direction shown by arrow B1 from such a state, the camslider 7 starts to move in a direction shown by arrow C1. Following tothe movement of the cam slider 7, not only the optical disc isunclamped, but also the boss 71 of the cam slider 7 pushes an inclinedportion 23 a of the guide groove 23, so that the tray 2 is moved in adirection shown by arrow A1. Thereby, the first rack 22 engages with thedrive gear 3, and. the tray 2 is continuously moved with drive gear 3 inthe direction shown by arrow A1.

As can be seen from FIG. 5B, when the tray 2 moves to a position justbefore the terminal point of drawing of the tray 2, the front endportion 73 of the cam slider 7 contacts the second stopper 25, first.Since the cam slider 7 is formed of a material having a coefficient ofelasticity smaller than that of the tray 2, it is possible to reduce theblow sound in comparison with that in a case that the cam slider 7 isformed of a material having substantially the same coefficient ofelasticity of that of the tray 2. The front end portion 73 of the camslider 7 serves as an elastically deformable member in this embodiment.

As can be seen from FIG. 5C, when the tray 2 is further moved in thedirection shown by arrow Al after contacting of the front end portion 73of the cam slider 7 with the second stopper 25, the front end portion 73of the cam slider 7 is elastically deformed due to pressure of thesecond stopper 25, and finally the first stoppers 24 of the tray 2contact with the third stoppers 83 of the main chassis 8. Since themoving speed of the tray 2 is decelerated largely due to elasticdeformation of the front end portion 73 of the cam slider 7, the blowsound due to the contact of the first stoppers 24 and the third stoppers83 can be radically reduced.

As described above, according to the optical disc apparatus 1 inaccordance with the embodiment of the present invention, the front endportion 73 of the cam slider 7 made of, for example, polyacetal which iselastically deformed easily contacts the second stopper 25 of the tray 2at a position just before the terminal position of drawing of the tray2, and the moving speed of the tray 2 is largely decelerated due toelastic deformation of the front end portion 73 of the cam slider 7.Thus, the blow sound due to contact of the first stoppers 24 of the tray2 with the third stoppers 83 of the main chassis 8 can be radicallyreduced. As a result, a quiet optical disc apparatus can be realized.

In addition, since polyacetal, which is an example of the material ofthe cam slider 7, is superior in wear resistance, it is no need tospread a fine particle lubricant on contacting portions of the secondstopper 25 of the tray 2 and the front end portion 73 of the cam slider7. Consequently, there is no fear to give bad influence to movement ofthe optical disc apparatus 1 due to scattering of the powder ingredientof the lubricant in the inside of the apparatus. Smoothness of thedrawing motion of the tray 2 can be maintained in long-term use.

Furthermore, the front end portion 73 of the cam slider 7, which isconventionally used for moving the movable chassis 6, is used todecelerate the moving speed of the tray 2 owing to elastic deformationthereof when the second stopper 25 of the tray 2 contacts thereto. Thus,it is possible to prevent cost increase of the optical disc apparatus 1without inviting increase of number of components of the apparatus.

In addition, as for the present invention, various kinds oftransformation is possible without it being limited to constitution ofthe above-mentioned embodiment. For example, another material can beused as a material of the cam slider 7, if it has a coefficient ofelasticity smaller than that of a material of the tray 2 and the mainchassis 8, without being limited to polyacetal. The other party wherethe second stopper 25 makes contact before the first stoppers 24 of thetray 2 contact the third stoppers 83 of the main chassis 8 may be anelastic spring member made of a material having a coefficient ofelasticity smaller than that of a material of the tray 2, without beinglimited to the front end portion 73 of the cam slider 7.

This application is based on Japanese patent application 2004-80435filed Mar. 18, 2004 in Japan, the contents of which are herebyincorporated by references.

Although the present invention has been fully described by way ofexample with reference to the accompanying drawings, it is to beunderstood that various changes and modifications will be apparent tothose skilled in the art. Therefore, unless otherwise such changes andmodifications depart from the scope of the present invention, theyshould be construed as being included therein.

1. An optical disc apparatus comprising: a main chassis; a tray, towhich an optical disc is disposed, movably held on the main chassis anddrawn from the main chassis in a predetermined direction; a drivingmechanism provided on the main chassis for reciprocally moving the trayin the predetermined direction; and an elastically deformable memberwhich contacts the tray just before a terminal position of drawing ofthe tray from the main chassis where the drawing motion of the tray isstopped in a manner so that moving speed of the tray is decelerated dueto elastic deformation of the elastically deformable member; wherein thedriving mechanism includes a cam slider, which is slidably held on themain chassis for moving a movable chassis around a pivot and serves asthe elastically deformable member; and wherein a front end portion ofthe cam slider contacts the tray.
 2. The optical disc apparatus inaccordance with claim 1, wherein a material of the elasticallydeformable member is superior to wear resistance and has a coefficientof elasticity smaller than that of a material of the tray.
 3. Theoptical disc apparatus in accordance with claim 2, wherein the materialof the elastically deformable member is polyacetal.
 4. The optical discapparatus in accordance with claim 1 further comprising: the movablechassis movably held on the main chassis in a direction perpendicular toa face of the tray on which the optical disc is disposed; and arevolving table, to which the optical disc is mounted, provided on themovable chassis.
 5. The optical disc apparatus in accordance with claim4, wherein the tray has a stopper which contacts with the front endportion of the cam slider when the tray reaches to a position justbefore the terminal position of drawing of the tray.
 6. The optical discapparatus in accordance with claim 5, wherein the tray further hasanother stopper which contacts with a stopper of the main chassis whenthe tray reaches to the terminal position of drawing of the tray.
 7. Anoptical disc apparatus comprising: a main chassis; a tray, to which anoptical disc is disposed, movably held on the main chassis and drawnfrom the main chassis in a predetermined direction; a movable chassismovably held on the main chassis in a direction perpendicular to a faceof the tray on which the optical disc is disposed; a driving mechanismprovided on the main chassis for reciprocally moving the tray in thepredetermined direction, and for moving the movable chassis around apivot; a revolving table, to which the optical disc is mounted, providedon the movable chassis; and an optical pickup provided on the movablechassis, and emitting laser beam for writing and/or reading data onand/or from the optical disc mounted on the revolving table while it hasbeen revolved; wherein the tray has a pair of first stoppers and asecond stopper; the main chassis has a pair of third stoppers to whichthe first stoppers contact when the tray reaches to a terminal positionof drawing motion of the tray; the driving mechanism includes a camslider for moving the movable chassis around the pivot, and made of amaterial superior to wear resistance and has a coefficient of elasticitysmaller than that of a material of the tray; and the second stopper ofthe tray contacts a front end portion of the cam slider when the trayreaches to a position just before the terminal position of drawing ofthe tray, so that the front end portion of the cam slider is elasticallydeformed, moving speed of the tray is decelerated, and consequently blowsound due to contact of the first stoppers with the third stoppers canbe reduced.
 8. An optical disc apparatus comprising: a main chassis; atray, to which an optical disc is disposed, movably held on the mainchassis and drawn from the main chassis in a predetermined direction; adriving mechanism provided on the main chassis for reciprocally movingthe tray in the predetermined direction; and an elastically deformablemember which contacts the tray just before a terminal position ofdrawing of the tray from the main chassis where the drawing motion ofthe tray is stopped in a manner so that a moving speed of the tray isdecelerated due to elastic deformation of the elastically deformablemember; a movable chassis movably held on the main chassis in adirection perpendicular to a face of the tray on which the optical discis disposed; and a revolving table, to which the optical disc ismounted, provided on the movable chassis; wherein the driving mechanismincludes a cam slider which is slidably held on the main chassis formoving the movable chassis around a pivot, and serves as the elasticallydeformable member.
 9. The optical disc apparatus in accordance withclaim 8, wherein the tray has a stopper which contacts with a front endportion of the cam slider when the tray reaches to a position justbefore the terminal portion of the drawing of the tray.
 10. The opticaldisc apparatus in accordance with claim 9, wherein the tray further hasanother stopper which contacts with a stopper of the main chassis whenthe tray reaches to the terminal position of drawing of the tray. 11.The optical disc apparatus in accordance with claim 8, wherein amaterial of the elastically deformable member is superior to wearresistance and has a coefficient of elasticity smaller than that of amaterial of the tray.
 12. The optical disc apparatus in accordance withclaim 11, wherein the material of the elastically deformable member ispolyacetal.